lamassu-server/lib/plugins/exchange/ccxt.js
2021-07-08 17:08:38 +01:00

52 lines
2.1 KiB
JavaScript

const { toUnit } = require('lamassu-coins')
const _ = require('lodash/fp')
const ccxt = require('ccxt')
const { buildMarket, ALL, isConfigValid } = require('../common/ccxt')
const { ORDER_TYPES } = require('./consts')
const DEFAULT_PRICE_PRECISION = 2
const DEFAULT_AMOUNT_PRECISION = 8
function trade (side, account, tradeEntry, exchangeName) {
const { cryptoAtoms, fiatCode, cryptoCode, tradeId } = tradeEntry
try {
const exchangeConfig = ALL[exchangeName]
if (!exchangeConfig) throw Error('Exchange configuration not found')
const { CUSTOM_KEY, loadOptions, loadConfig = _.noop, REQUIRED_CONFIG_FIELDS, ORDER_TYPE, AMOUNT_PRECISION } = exchangeConfig
if (!isConfigValid(account, REQUIRED_CONFIG_FIELDS)) throw Error('Invalid config')
const symbol = buildMarket(fiatCode, cryptoCode, exchangeName)
const precision = _.defaultTo(DEFAULT_AMOUNT_PRECISION, AMOUNT_PRECISION)
const amount = toUnit(cryptoAtoms, cryptoCode).toFixed(precision)
const accountOptions = _.isFunction(loadOptions) ? loadOptions(account) : {}
const withCustomKey = CUSTOM_KEY ? { [CUSTOM_KEY]: tradeId } : {}
const options = _.assign(accountOptions, withCustomKey)
const exchange = new ccxt[exchangeName](loadConfig(account))
if (ORDER_TYPE === ORDER_TYPES.MARKET) {
return exchange.createOrder(symbol, ORDER_TYPES.MARKET, side, amount, null, options)
}
return exchange.fetchOrderBook(symbol)
.then(orderBook => {
const price = calculatePrice(side, amount, orderBook).toFixed(DEFAULT_PRICE_PRECISION)
return exchange.createOrder(symbol, ORDER_TYPES.LIMIT, side, amount, price, options)
})
} catch (e) {
return Promise.reject(e)
}
}
function calculatePrice (side, amount, orderBook) {
const book = side === 'buy' ? 'asks' : 'bids'
let collected = 0.0
for (const entry of orderBook[book]) {
collected += parseFloat(entry[1])
if (collected >= amount) return parseFloat(entry[0])
}
throw new Error('Insufficient market depth')
}
module.exports = { trade }